参数资料
| 型号： | NCP1207BDR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 8/17页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM CM OVP OCP HV 7SOIC |
| 标准包装： | 1 |
| 输出隔离： | 隔离 |
| 频率范围： | 200kHz |
| 输入电压： | 10.6 V ~ 20 V |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽）7 引线 |
| 供应商设备封装： | 7-SOIC |
| 包装： | 标准包装 |
| 其它名称： | NCP1207BDR2GOSDKR |
NCP1207A, NCP1207B
becomes mainsPEAK ? 2 . Our power contribution
The DSS behavior actually depends on the internal IC
consumption and the MOSFET’s gate charge Qg. If we
select a MOSFET like the MTP2N60E, Qg equals 22 nC
(max). With a maximum switching frequency selected at
75 kHz, the average power necessary to drive the MOSFET
(excluding the driver efficiency and neglecting various
voltage drops) is:
Fsw ? Qg ? V CC with:
Fsw = maximum switching frequency
Qg = MOSFET’s gate charge
V CC = V GS level applied to the gate
To obtain the output current, simply divide this result by
V CC : I driver = F SW ? Qg = 1.6 mA. The total standby power
consumption at no--load will therefore heavily rely on the
internal IC consumption plus the above driving current
(altered by the driver ’s efficiency). Suppose that the IC is
supplied from a 350 VDC line. The current flowing through
pin 8 is a direct image of the NCP1207A/B consumption
(neglecting the switching losses of the HV current source).
If I CC2 equals 2.3 mA @ T J = 60 ? C, then the power
dissipated (lost) by the IC is simply: 350 V x 2.3 mA =
805 mW. For design and reliability reasons, it would be
interested to reduce this source of wasted power that
increase the die temperature. This can be achieved by using
different methods:
1. Use a MOSFET with lower gate charge Qg.
2. Connect pin 8 through a diode (1N4007 typically) to
one of the mains input. The average value on pin 8
V
π
example drops to: 223 V x 2.3 mA = 512 mW. If a
resistor is installed between the mains and the diode,
you further force the dissipation to migrate from the
package to the resistor. The resistor value should
account for low--line startups.
When using Figure 13 option, it is important to check
the absence of any negative ringing that could occur
on pin 8. The resistor in series should help to damp
any parasitic LC network that would ring when
suddenly applying the power to the IC. Also, since
the power disappears during 10 ms (half--wave
rectification), CV CC should be calculated to supply
the IC during these holes in the supply
3. Permanently force the V CC level above V CCH with
an auxiliary winding. It will automatically
disconnect the internal startup source and the IC will
be fully self--supplied from this winding. Again, the
total power drawn from the mains will significantly
decrease. Make sure the auxiliary voltage never
exceeds the 16 V limit.
Skipping Cycle Mode
The NCP1207A/B automatically skips switching cycles
when the output power demand drops below a given level.
This is accomplished by monitoring the FB pin. In normal
operation, Pin 2 imposes a peak current accordingly to the
load value. If the load demand decreases, the internal loop
asks for less peak current. When this setpoint reaches a
determined level, the IC prevents the current from
decreasing further down and starts to blank the output
pulses: the IC enters the so--called skip cycle mode, also
named controlled burst operation. The power transfer now
depends upon the width of the pulse bunches (Figure 14) and
follows the following formula:
2
1 ? Lp ? Ip 2 ? Fsw ? D burst with:
Lp = primary inductance
Fsw = switching frequency within the burst
Ip = peak current at which skip cycle occurs
D burst = burst width / burst recurrence
HV
5
1N4007
300
MAX PEAK
CURRENT
NORMAL CURRENT
MODE OPERATION
MAINS
1
2
C bulk
1
2
8
7
6
200
SKIP CYCLE
CURRENT LIMIT
3
4
6
5
100
Figure 13. A simple diode naturally reduces the
average voltage on Pin 8
0
WIDTH
RECURRENCE
Figure 14. The skip cycle takes place at low peak
currents which guaranties noise free operation
http://onsemi.com
8
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP1207-D | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:PWM Current-Mode Controller for Free Running Quasi-Resonant Operation |
| NCP1207DR2 | 功能描述:IC CTRLR PWM CM OVP OCP HV 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - AC-DC 转换器，离线开关 系列:- 标准包装:1 系列:FPS™ 输出隔离:隔离 频率范围:61kHz ~ 73kHz 输入电压:8 V ~ 26 V 输出电压:650V 功率（瓦特）:12W 工作温度:-40°C ~ 115°C 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-MDIP 包装:Digi-Reel® 其它名称:FSL206MRBNFSDKR |
| NCP1207DR2G | 功能描述:IC CTRLR PWM CM OVP OCP HV 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - AC-DC 转换器，离线开关 系列:- 标准包装:1 系列:FPS™ 输出隔离:隔离 频率范围:61kHz ~ 73kHz 输入电压:8 V ~ 26 V 输出电压:650V 功率（瓦特）:12W 工作温度:-40°C ~ 115°C 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-MDIP 包装:Digi-Reel® 其它名称:FSL206MRBNFSDKR |
| NCP1207P | 功能描述:IC CTRLR PWM CM OVP OCP HV 8DIP RoHS:否 类别:集成电路 (IC) >> PMIC - AC-DC 转换器，离线开关 系列:- 标准包装:1 系列:FPS™ 输出隔离:隔离 频率范围:61kHz ~ 73kHz 输入电压:8 V ~ 26 V 输出电压:650V 功率（瓦特）:12W 工作温度:-40°C ~ 115°C 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-MDIP 包装:Digi-Reel® 其它名称:FSL206MRBNFSDKR |
| NCP1207PG | 功能描述:IC CTRLR PWM CM OVP OCP HV 8DIP RoHS:是 类别:集成电路 (IC) >> PMIC - AC-DC 转换器，离线开关 系列:- 标准包装:1 系列:FPS™ 输出隔离:隔离 频率范围:61kHz ~ 73kHz 输入电压:8 V ~ 26 V 输出电压:650V 功率（瓦特）:12W 工作温度:-40°C ~ 115°C 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-MDIP 包装:Digi-Reel® 其它名称:FSL206MRBNFSDKR |
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